Update: Per an announcement from the MBTA, the substance found on the bus was "common chalk." The bus operator has been released from the hospital. This morning, a hazmat team was called into the Haymarket T stop when a Route 111 bus driver noticed a strange powder on the dashboard of her bus at about 9:15. Traffic ugliness ensued, but things should be cleared up now. The Herald reached Joe Pesaturo, who had word on......